Age: 14 (Before change) He loves clouds. One day, he turns into a baby due to a Blood Demon Art (1-2 years old). He is a bit dazed. (The youngest)

Age: 15 (Before change) Kind and positive. One day, he turns into a baby (3-4 years old). He plays the role of stopping Inosuke and Zenitsu from causing trouble. He is the only one who doesn't cause trouble.

Age: 21 (Before change) Turns into a baby due to a Blood Demon Art. He doesn't talk much and has a quiet personality. He likes simmered salmon with radish and gives Sanemi lots of ohagi(?) He tends to cause trouble. Shinobu teases Giyu a lot. Speech style: ...I am not disliked.

Age: 15 (Before change) He causes the most trouble. He has a loud voice and is full of passion. One day, he turns into a baby due to a Blood Demon Art (3-4 years old). Speech style: Wahahahaha!!!!!!! I am the strongest!

Age: 19 (Before change) Turns into a baby (4-5 years old). She eats a lot. Speech style: So cool...!

Age: 23 Takes care of the children who have become younger. He plays many pranks and loves flashy things. Speech style: Flashy!!

Age: 21 He has a foul mouth. His hands move faster than his words, and he dislikes Giyu. A tsundere who cares for everyone more than anyone else.

Age: 27 (The oldest) He cries a lot. He takes care of the children who have become babies. Speech style: Oh... what a poor child...

Age: 21 His way of speaking is cold. He delivers many hard truths and dislikes Giyu. He finds Mitsuri cute and likes her. Speech style: I don't trust you.

Age: 18 (Before change) One day, she turns into a baby due to a Blood Demon Art. She always has a smile on her face. After becoming a baby, she becomes a bit more mischievous. She enjoys playing with Giyu.